Solid Propellant Rockets

The modeling activity on Solid Rocket Booster covers several aspects affecting the performance of a motor, dealing both with the nominal performance and with the evaluation of the effects caused by defects and manufacturing issues. In the design and development of a new solid propellant rocket motor (SRM), the use of numerical tools able to simulate, predict and reconstruct the behavior of a given motor, in all its operative conditions is crucial: more accurate performance predictions would reduce the need of expensive testing, thus decreasing the cost of development for each SRM. The main factor influencing the combustion chamber pressure, and hence the thrust, is the time evolution of the burning surface and the surface regression rate. In the real motor a lot of factors affect the propellant combustion resulting both in propellant rate variation from the expected theoretical one and thermal protections exposure prior than expected. The simulation tool that has been developed al Alma Propulsion Laboratory is capable to evaluate both the ideal combustion surface regression and the evolution that takes place when defects (like for example air inclusions, debondings, …) are present.